Inflammation is a vital protective mechanism in mammals, helping minimize the impact of injurious stimuli on the structure and function of mammalian systems affected by such stimuli. In a simplistic description of the inflammatory process, the body's white blood cells, chemicals (inflammatory mediators) and plasma rush to the area affected by foreign substances such as bacteria, viruses and other harmful stimuli. This mobilization helps protect mammals from infection and injury, but may also trigger a cascade of events leading up to physiological sequelae.
Inflammation may be acute or chronic. The acute form of inflammation may last from a few minutes to a few days. The chronic form of inflammation, which may last from months to years, may impact and change the cells in affected area. Inflammation plays a critical role in wound healing, for example. At times, however, the body's extended inflammatory response may cause chronic wounds, or take place even in the absence of foreign substances, causing damage to its own tissues. At other times, extended/prolonged response of this protective mechanism results in discomfort of functional or cosmetic nature. In these situations, methods of containing or reversing inflammation may have to be employed.
Inflammation is believed to be a major mediator of a wide range of acute and chronic diseases. Such misdirected inflammation is present in many diseases, such as arthritis, tendonitis, bursitis and similar conditions. Inflammation may affect organs as part of an autoimmune disorder. The types of symptoms depend on which organs are affected. Examples include inflammation of the heart (myocarditis, which may cause chest pain or fluid retention), inflammation of the small tubes that transport air to the lungs (bronchiolitis, which may cause shortness of breath similar to an asthma attack), inflammation of the kidneys (nephritis, which may cause high blood pressure or kidney failure), inflammation of the large intestine (colitis, which may cause cramps and diarrhea), inflammation of the eye (iritis or uveitis, which may cause pain or decreased vision), inflammation of the muscles (polymyositis, which may cause achiness or weakness), and inflammation of the blood vessels (vasculitis, which may cause rash, headaches, or internal organ damage). Pain may not be a main symptom of these inflammatory syndromes since many organs have very few pain-sensitive nerves. Treatment of organ inflammation should be directed at the cause of inflammation whenever possible.
Although inflammation is a necessary part of the body's defense system, excessive, prolonged or misdirected inflammation may result in chronic diseases that may be debilitating. Current treatment options are limited and include anti-inflammatory drugs which are mainly comprised of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids, but the chronic administration of these compounds often cause problems in patients. Healthcare professionals lack any alternative with better safety and side-effects profiles than these compounds.
Volatile anesthetics have been used safely for decades as general anesthetics. Besides producing analgesia, volatile anesthetics affect other receptors and have been shown to have anti-inflammatory and muscle relaxing properties when administered by inhalation and in vitro. Volatile anesthetics have been shown to reduce cytokine production and release in both in vivo and in vitro inflammation model, and downregulate lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines. Additionally, volatile anesthetics have been shown to inhibit neutrophil function and decrease time to resolution of inflammation. However, volatile anesthetics have not been successfully used in the local treatment of inflammation.
There is a need in the art for improved formulations that may be used in the treatment of inflammation. There is also a need in the art for improved methods for treating misdirected or prolonged inflammation. The current invention fulfills these needs.